Non-woven material for medical compresses

ABSTRACT

Curled non-woven material formed of waves such as contiguous anti-nodes (9,10) of adjacent waves consist of small adjacent pads (11,12) located on the same side of the median plan (8) of the non-woven material. 
     Use: Medical and surgical compresses 
     FIG. 3.

The present invention relates to a non-woven material whose curly orwavy structure enables it to be used in particular as a medical orsurgical compress.

At present, medical compresses are obtained from a light fabric--calleddressing gauze--(weight between 25 and 28 g/m²) whose manufacturerequires the utilization of a costly and inefficient material. Thisfabric is then folded and cut into several sizes; each compress is thenin general wrapped individually and sterilized.

Compresses made of conventional gauze are very flat products, adheringto wounds and having quite a low fluid absorption coefficient. Inaddition, their elasticity and resilience characteristics are veryclearly insufficient.

The aim of much research work has been to replace the gauze by non-wovenmaterials obtained by a dry process, wet process or so-called"spun-bonded" method and compounds of mixtures of synthetic and/ornatural fibers. Although the properties of non-woven compresses areappreciably superior to those made from gauze, particularly as regardsnon-adhesion to wounds, they nevertheless are still far from meetingrequirements as regards absorption.

The present invention relates to a non-woven material mitigating thedisadvantages of non-woven materials and conventional gauze. Itsparticular structure enables properties such as high absorptioncapacity, non-adherence to wounds, elasticity, and resilience to becombined.

In general, this non-woven material has a succession of uniformlydistributed waves whose anti-nodes are alternatively located above andbelow the medium plane of the non-woven material.

In particular, the continuous anti-nodes of two adjacent waves, locatedon the same side of the medium plane of the non-woven material, consistof small adjacent pads.

According to one embodiment of the invention, the non-woven material isa composite consisting of synthetic netting on which a web of cellulosefibers is fixed, in particular by thermo-bonding.

The invention will be better understood with the aid of the drawings,which represent non-limitative examples of the design of the non-wovenmaterial:

FIG. 1 is a view of the non-woven material from below;

FIG. 2 is a sectional view of FIG. 1 in a plane parallel to themachining direction of the non-woven material;

FIG. 3 is a sectional view of FIG. 1 in a plane perpendicular to themachining direction of the non-woven material;

FIG. 4 is a perspective view of a non-woven material of a syntheticnetting and a cellulose fiber web.

FIG. 1 is a view from below the non-woven material (1) which has amachining direction (2), corresponding to the longitudinal direction ofthe manufacture of said non-woven material, and a crosswise direction(3) perpendicular to the machining direction (2). This non-wovenmaterial (1) comprises evenly spaced waves or curls positioned along thelines (5) parallel to the machining direction (2).

FIG. 2, which is a sectional view of FIG. 1 along 2--2, in a planeparallel to the machining direction (2) shows that the non-wovenmaterial has waves (4) whose anti-nodes (6,7) are alternatively aboveand below the median plane (8).

FIG. 3 which is a sectional view of FIG. 1 along 3--3, in a planeperpendicular to the machining direction (2) shows that the contiguousanti-nodes (9,10) of adjacent waves consist of small adjacent pads(11,12) located on the same side of the median plane (8) of thenon-woven material. Beyond the sectional plane is seen an outline of thepads located below the median plane (8). The height and width of thesepads are between 0.1 and 3 mm.

FIG. 4 shows a preferred embodiment of the invention; the non-wovenmaterial consists of a synthetic netting (13) consisting of filaments(15) of a first polymer inside a sheath of a second polymer andconnected by fine lamellas (16) of a second polymer, forming a nettingon the surface of which is deposited a cellulose fiber web (14).

The web (14) is thermo-bonded to the netting (13); the non-wovenmaterial, therefore, does not include any chemical binder and can,therefore, be used both as a medical and a surgical compress.

According to a preferred embodiment of the invention, the syntheticnetting (13) is a double-stretched netting comprising in the machiningdirection (2) parallel polyamide filaments (15) separated by a uniformdistance between 0.1 and 3 mm and connected to one another by narrowstrips of polypropylene (16), separated regularly by a distance between0.1 and 3 mm and perpendicular to the filaments (15). The web (14) ofthe cellulose fibers consists of a cotton fiber web.

In addition, this non-woven material has the advantage of being lighterin weight than conventional gauze. The netting (13) has a weight ofbetween 5 and 15 g/m², preferably 7 g/m² and the cellulose fiber web(14) a weight between 10 and 20 g/m², preferably 16 g/m². Its bulkdensity is less than 0.15--preferably 0.1, and its absorption capacityis greater than 13 cm³ /g--preferably 16 cm³ /g.

The table below gives the results of measurements made on non-wovenmaterial according to the invention, on conventional gauze, and on acommerical non-woven material called PELY-TEX:

    ______________________________________                                                 Non-Woven Material                                                            According To The     PELY-TEX                                                 Invention    Gauze   23VI                                            ______________________________________                                        Weight g/m.sup.2                                                                         24             25      23.7                                        Thickness mm (1)                                                                         2.40           1.50    1.40                                        Density    0.1            0.17    0.17                                        Absorption Rate                                                                          8              60      45                                          sec. (2)                                                                      Absorption 16             12      12.7                                        Coefficient                                                                   cm.sup.3 /g (3)                                                               ______________________________________                                         (1) The thickness is defined as the thickness of 10 superimposed sheets       measured under a pressure of 20 g/cm.sup.3.                                   (2) The absorption rate is defined as the time taken by a drop of water o     1/20 cm.sup.3 deposited on the surface of said nonwoven material with a       pipette to penetrate the nonwoven material.                                   (3) The absorption coefficient is determined according to the CODEX           standard applicable to cotton wool.                                      

The very special structure of the non-woven material according to theinvention enables compresses to be manufactured which are:

very absorbent because of the pads described above and the presence ofthe cellulose fiber web;

non-adherent to wounds because of a mode of folding such that the partsdesigned to come into contact with the wound consists of the baresynthetic netting;

elastic because of the presence of uniformly distributed waves;

resilient because of the framework consisting of the synthetic netting.

We claim:
 1. Non-woven material for a medical or surgical compresshaving a machining direction and a crosswise direction, characterized inthat it has a succession of waves uniformly distributed along the linesparallel to the machining direction and whose adjacent anti-nodes arealternatively located above and below the median plane of said non-wovenmaterial and in that it comprises a synthetic netting having a cellulosefiber web thermobonded to one of its faces.
 2. Non-woven materialaccording to claim 1, characterized in that the contiguous anti-nodes oftwo adjacent waves, located on the same side of the median plane,consist of small adjacent pads.
 3. Non-woven material according to claim2, characterized in that the height of each pad above the median planeis between 0.1 and 3 mm.
 4. Non-woven material according to claim 3,characterized in that the width of each pad is between 0.1 and 3 mm. 5.Non-woven material according to claim 1, characterized in that thesynthetic netting is a double-stretch netting comprising in themachining direction parallel polyamide filaments separated evenly by adistance between 0.1 and 3 mm, connected to one another by narrow stripsof polypropylene separated regularly by a distance between 0.1 and 3 mmperpendicular to the filaments.
 6. Non-woven material according to claim1, characterized in that the cellulose fiber web is a cotton fiber web.7. Non-woven material according to claim 5, characterized in that theweight of the synthetic netting is between 5 and 15 g/m² and that thecellulose fiber web between 10 and 20 g/m².
 8. Non-woven materialaccording to claim 7, characterized in that the weight of the syntheticnetting is about 7 g/m² and that of the cotton fiber web is about 16g/m².
 9. Non-woven material according to claim 8, characterized in thatits bulk density is less than 0.15 and its water absorption coefficientgreater than 13 cm³ /g.
 10. Non-woven material according to claim 9,characterized in that its bulk density is about 0.1 and its absorptioncoefficient is about 16 cm³ /g.
 11. Non-woven material according toclaim 10, characterized in that its thickness is about 0.24 mm.
 12. Amedical compress manufactured from non-woven material according to claim1, characterized in that the material is folded in a way such that thepart designed to come into contact with the wound is constituted of abare synthetic netting.